Lysine enrichment of wheat flour: prolonged feeding of infants.

White wheat flour enriched with lysine was the only source of protein in the diet of six convalescent malnourished infants for 3-6 months. At 8% protein calories the equivalents of 0.1, 0.2, and 0.4% lysine enrichment were equally effective in supporting normal linear growth, weight gain, nitrogen retention, serum proteins, plasma amino acids, and liver morphology. Between 6.4 and 7.3% protein calories there was almost certainly an advantage to 0.2% over 0.1% enrichment, and possible to 0.4% over 0.2% enrichment, by the same parameters. Ifwheat is to be enriched with lysine in those areas where it is the main source of protein for many infants and small children, and where dilution by nonprotein calories is the rule, at least 0.2% enrichment is recommended.